issue on Ubuntu, node 7

[shahidkarimi]

! node-stringprep@0.8.0 install: node-gyp rebuild
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the node-stringprep@0.8.0 install script 'node-gyp rebuild'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the node-stringprep package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! node-gyp rebuild
npm ERR! You can get information on how to open an issue for this project with:
npm ERR! npm bugs node-stringprep
npm ERR! Or if that isn't available, you can get their info via:
npm ERR! npm owner ls node-stringprep
npm ERR! There is likely additional logging output above.

npm ERR! Please include the following file with any support request:
npm ERR! /root/.npm/_logs/2017-05-14T01_21_40_470Z-debug.log